Correlation Between Primary Si and Silicide Refinement Induced by Ultrasonic Treatment of Multicomponent Al–Si Alloy Containing Ti, Zr, V, and P

Jae‑Gil Jung,Young‑Hee Cho,Tae‑Young Ahn,Jae‑Hee Yoon,Sang‑Hwa Lee,Jung‑Moo Lee 대한금속·재료학회 2019 METALS AND MATERIALS International Vol.25 No.5

The correlation between primary Si and silicide refinement induced by ultrasonic treatment (UST) of multicomponent Al–Sialloy containing Ti, Zr, V, and P was investigated. UST significantly refined the primary Si phase owing to cavitation-inducedwetting and deagglomeration of MgAl2O4particles. Lowering the UST finish temperature caused deterioration of the degreeof primary Si refinement, instead leading to silicide refinement. Cavitation-induced silicide nucleation on wetted MgAl2O4consumed the MgAl2O4particles, particularly in the case of primary Si nucleation. Similarly, the formation of an AlP phaseon the silicide phase reduced the nucleation efficiency of the AlP phase. Poisoning of the MgAl2O4and AlP phases by thesilicide phase was responsible for the deterioration in primary Si refinement. Room-temperature tensile strength and hightemperatureelongation were increased by UST and were dependent on the size of primary Si.

A Comparison of Lyophilized Amniotic Membrane with Cryopreserved Amniotic Membrane for the Reconstruction of Rabbit Corneal Epithelium

Ahn Jae-Il,Jang In-Keun,Lee Doo-Hoon,Seo Young-Kwon,Yoon Hee-Hoon,Shin Youn-Ho,Kim Jae-Chan,Song Kye-Yong,Lee Hee-Gu,Yang Eun-Kyung,Kim Ki-Ho,Park Jung-Keung The Korean Society for Biotechnology and Bioengine 2005 Biotechnology and Bioprocess Engineering Vol.10 No.3

Many researchers have employed cryopreserved amniotic membrane (CAM) in the treatment of a severely damaged cornea, using corneal epithelial cells cultured on an amniotic membrane (AM). In this study, two Teflon rings were made for culturing the cells on the LAM and CAM, and were then used to support the AM, which is referred to in this paper as an Ahn's AM supporter. The primary corneal epithelial cells were obtained from the limbus, using an ex-plantation method. The corneal epithelium could be reconstructed by culturing the third­passage corneal epithelial cells on the AM. A lyophilized amniotic membrane (LAM) has a higher rate of graft take, a longer shelf life, is easier to store, and safer, due to gamma irradiation, than a (AM. The corneal epithelium reconstructed on the LAM and (AM, supported by the two­Teflon rings, was similar to normal corneal epithelium. However, the advantages of the LAM over that of the (AM make the former more useful. The reconstruction model of the corneal epithelium, using AM, is considered as a good in vitro model for transplantation of cornel epithelium into patients with a severely damaged cornea.

Reconstruction of Rabbit Corneal Epithelium on Lyophilized Amniotic Membrane Using the Tilting Dynamic Culture Method

Ahn, Jae-Il,Lee, Doo-Hoon,Ryu, Yang-Hwan,Jang, In-Keun,Yoon, Mun-Young,Shin, Youn Ho,Seo, Young-Kwon,Yoon, Hee-Hoon,Kim, Jae-Chan,Song, Kye-Yong,Yang, Eun-Kyung,Kim, Ki-Ho,Park, Jung-Keug Blackwell Publishing Inc 2007 Artificial Organs Vol.31 No.9

<P>Abstract: </P><P>Rabbit corneal epithelium was reconstructed using tilting dynamic culture with a self-manufactured, amniotic membrane (AM) supporter and a lyophilized amniotic membrane (LAM). Rabbit corneal epithelial (RCE) cells were cultured and cryopreserved after isolation from the limbus. The second- and third-passage RCE cells were plated onto the epithelial side of the LAM of Ahn's AM supporter. Two days later, the air–liquid interface culture was maintained with third-passage RCE cells for 6 days and second-passage corneal epithelial cells for 9 days. The average viability of thawed RCE cells, assessed using trypan blue dye exclusion, was 77.42%. The reconstructed corneal epithelium was characterized by histological (hematoxylin and eosin) and immunohistochemical staining (proliferating cell nuclear antigen) for light microscopy, and by reverse transcriptase-polymerase chain reaction, glucose assay, and transmission electron microscopy. The basal layer of the reconstructed corneal epithelium was well formed, and the epithelium was tightly constructed due to the increase in cell proliferation and differentiation caused by the tilting dynamic culture, as opposed to static culture. Tilting dynamic culture was useful for the reconstruction of the epithelium using easily damaged epithelial cells and resulted in more stratum cell layers. Moreover, cytokeratin (CK3) mRNA expression in tilting dynamic cultured third-passage RCE cells seeded onto AM was greater than in static cultured third-passage RCE cells. The morphology of the reconstructed corneal epithelium on LAM by tilting dynamic culture for 9 days resembled that of the skin epidermis. This was thought to be because the tilting dynamic culture not only accelerated the proliferation and differentiation of cells by physical or mechanical stimulation, but also ensured that the supply of medium was delivered to the basal cells more efficiently. Thus, the reconstruction of the corneal epithelium using LAM and tilting dynamic culture was considered to be a good in vitro model for autologous or allogeneic transplantation of corneal epithelium and skin epidermis in patients with damaged epithelia. </P>

전통누룩 진균류를 이용한 입국의 제조 및 입국곰팡이의 동정

김재호 ( Jae Ho Kim ),권영희 ( Young Hee Kwon ),이애란 ( Ae Ran Lee ),김혜련 ( Hye Ryun Kim ),안병학 ( Byung Hak Ahn ) 한국균학회 2012 韓國菌學會誌 Vol.40 No.4

Various koji were prepared by fungi isolated from traditional nuruk and their quality characteristics were investigated. Acidity and saccharification power of their koji were ranged in 5.0~6.8 and 128sp~241sp. Nine fungi which were showed good quality and sensory evaluation were identified by analysis of their nucleotide sequences with PCR-amplified 18S rDNA internal transcribed spacer-1(ITS-1) and ITS-4 genes. Among them, six strains were identified as Aspergillus oryzae and the other strains were identified as Mycocladus corymbiferus, Rhizopus oryzae, Lichtheimia corymbifera.

2003년 국내 중증급성호흡기증후군 진료 현황 및 문제점 분석

이진수,김은실,정문현,백제중,정선화,안주희,최영화,이선희,고철우,김성범,김민자,박승철,기현균,송재훈,최상호,김양수,이상오,조용균,박영훈,정숙인,김연숙,이흥범,손창희,장성희,정희진,김우주 대한감염학회 2004 감염과 화학요법 Vol.36 No.3

목적 : 2002년 말 중국에서 SARS가 발생한 이후 국내에서도 2003년 10월까지 총 3명의 추정환자, 17명의 의심환자가 보고되었다. 향후 추가적인 SARS의 유행이 우려되는 상황에서, 그간의 SARS 환자 진료에 있어서의 실질적인 준비사항, 진료 현황 등에 대한 조사를 통해 문제점을 파악하여, 향후 더 나은 대비가 될 수 있도록 개선점을 제시하고자 하였다. 재료 및 방법 : SARS로 의심되는 환자를 진료 경험이 있는 병원의료진을 대상으로 2003년 10월에 설문조사를 실시하였다. 설문에는 SARS 환자 진료 시의 실질적인 조치, 진료 현황, 병실, 응급실 및 외래에서의 격리 시설과 준비사항, 보건당국의 관리와 지원에 관한 사항을 포함하였다. 결과 : 대상이 되는 22개 병원 중 17개(17/22, 77.2%) 병원이 설문에 응하였다. SARS 환자를 위한 격리실은 응급실, 외래, 일반병실 및 중환자실에서 각각 9개(9/17, 52.9%), 5개(5/17, 29.4%), 15개(15/16, 93.7%), 4개(4/16, 25%) 병원에서 음압처리가 되어있지 않은 일인실 혹은 다인실이 사용되었고, 1개(1/16, 6.3%) 병원에서만 일반병실에서 음압격리실이 운영되었다. 입원환자의 진찰 시 개인보호구의 착용은 거의 모든 의료기관에서 이루어졌다. 보건당국에서 SARS지정병원의 시설 등을 사전에 확인한 곳은 1곳(1/12, 8.3%)이였고, 14개 병원(14/15, 93.3%)에서는 보건당국에 의뢰한 검사결과를 통하 받지 못하였다. 결론 : 의료기관에서 SARS 환자용 격리실뿐만 아니라 기존의 격리실 설비 등이 미흡하였으며, 특히 중환자실 및 외래의 준비가 더욱 부족하였다. 보건당국의 의료기관에 대한 종합적인 지원이 부족하였고, 병원과의 원활한 연계가 잘 이루어지지 않았다. SARS 만이 아닌 격리를 필요로 하는 질환의 적절한 진료를 위해 향후 병원 시설의 정비와 정부차원에서의 보다 구체적이고 실질적인 대책마련이 필요하다. Background : There was an worldwide outbreak of the Severe Acute Respiratory Syndrome (SARS) originated from China in late 2002. During that period three cases of suspected SARS and 17 cases of probable SARS were reported in Korea. With the concerns about the reemergence of SARS-coV transmission, it is important to be prepared for any possibility. So, this study is aimed to analysis the past measures in managing SARS and propose the amendatory plans to improve the preparedness. Materials & Methods : Questionnaires were collected among clinicians with any experience in managing the probable or suspected SARS cases in Oct. 2003. 17 out of 22 hospitals responded to the questionnaire. The contents in the questionnaire were practical activities, personal equipments, response plans, isolation facilities in emergency centers, outpatient clinics, general wards and intensive care units, and relationship with the public health department. Results : The dedicated isolation rooms in emergency centers, outpatient clinics, general wards, and intensive care units were prepared in 9 (9/17, 52.9%), 5 (5/17, 29.4%), 15 (15/16, 93.7%), and 4 (4/16, 25.0%) hospitals, respectively. Except for one hospital that newly made negative pressure room for SARS, single or multi-bed rooms without airborne infection control were used in all the other hospitals. The personal precaution principles were kept quite well in general wards. Before the designation of SARS hospital by the public health department prior evalution to see if the hospital was suitable for managing SARS was conducted in only 1 (1/12, 8.3%) hospital. The results of laboratory diagnosis were reported back in 1 (1/15, 6.6%) hospital. Conclusions : The isolation facilities which can control airborne infection were almost deficient not only for SARS but also for other respiratory transmissible diseases. For the infection control of transmissible diseases including SARS, more investment is needed on medical facilities and comprehensive support from the public health department required.

Aluminum 合金材 Frame을 利用한 壁體거푸집工法의 實用化를 위한 工事費 分析에 관한 硏究

안재철,안진봉,정민수,강병희 東亞大學校 建設技術硏究所 2000 硏究論文集 Vol.24 No.2

This study is to investigate economical efficiency of using ALWOOD Form compared with that of EURO Form. ALWOOD Form is improved in the capacity in the wall-concrete structure in stead of using the existing form which has problems such as, the loss of labor when it is constructed or disjointed, and it's economical efficiency compared with that of EURO Form. The price of ALWOOD Form is more expensive than that of EURO Form due to its main material, aluminum-compound metal, composing frames. In a consequence, the cost of materials per unit area is increased. However, labor cost of ALWOOD Form based on the result of mobilization of manpower in construction field is saved due to the reduction of labor in using ALWOOD Form compared with that of EURO Form. As a result, using ALWOOD Form is more economical than that of EURO Form because saving labor cost which plays a major part in cost saving in formwork is more effective in retrenching total cost than increment of material cost. 철근 콘크리트조 건축공사에서 거푸집공사는 전체 공사기간 중에서 25% 정도의 비중을 차지하며, 단일 공종으로서는 상당히 긴공기를 필요로 하는 공사이다. 따라서, 거푸집공사는 주공정 (critica1 path)이 되고 있으며, 구조체 공사비의 30-40%, 전체공사비의10% 정도를 차지하므로 공기단축과 원가절감을 도모하는데 핵심적인 위치를 차지하고 있다. 이러한 거푸집공사는 최근 건설현장의 기능인력 부족과 노무비 상승, 3D업종의 기피,공사규모의 대형화,고층화 등의 사회환경의 변화와 많은 기술환경의 변화에 따라 거푸집의 대형화, 경량화, 기계화, 단순화, Unit화 그리고 높은 전용횟수를 요구하게 되었다. 그러나 현재 RC조 고층 벽식 구조물의 거푸집 공법으로 범용되고 있는 시스템화 거푸집의 일종인 “EURO Form"은 중량이 커서 부재의 크기가 작고 해체, 조립의 반복에 따른 인력의 소모가 많으며, 이음부위 면처리 비용이 많이 드는 등의 단점이 있어 이에 대한 보완이 필요한 실정이다. 따라서 이러한 문제점을 개선하기 위해 비중이 낮고 성형성이 우수하여 합리척인 설계가 가능한 알루미늄 합금재 프레임을 이용한 거푸집공법(이하 ALWOOD Form 공법)이 개발되어 일부 건설현장에서 시범 적용중에 있으나 원가관리를 위한 기초 자료가 부족하여 그 적용이 곤란한 실정이다. 따라서 본 연구는 ALWOOD Form과 EURO Fonn의 공사바 비교 · 분석을 통해 건설현장에서 거푸집공법 선정시 원가관리 측면에서의 기초자료를 제공하는데 그 목적이있다.

廢 EPS 再生 잉고트의 輕量 잔骨材 活用方案에 관한 實驗的 硏究

안재철,정민수,강병희 동아대학교 건설기술연구소 2000 硏究報告 Vol.24 No.1

This study is to investigate the possibility of using recycled EPS ingot as fine aggregate and to set basic data of the efficient mixing design for making lightweight concrete. The condition of the most efficient mix design for making lightweight concrete is that under the replacement ratio of 100%, if cement content is 400㎏/㎥ W/C ratio is 55%, if cement content is 450㎏/㎥ W/C ratio is 50%, 55%. From the result of the experiment under conditions, we could make the concrete whose qualities are slump value of over 18.2㎝, unit weight of less 2.00t/㎥, and compressive strength of over 222.57㎏f/㎠ when the cure duration is 28 days.

개인심리훈련이 역도선수의 경기력에 미치는 영향 : 여자선수를 중심으로

안효작,박영희,김동희,허재홍 한국체육대학교 학생생활연구소 1999 學生生活硏究 Vol.- No.5

燒成 黃土 모르터의 美匠材料 活用方案에 관한 硏究

안재철,강병희 東亞大學校 建設技術硏究所 1999 硏究論文集 Vol.23 No.1

This study aims to experiment the stability of plastering material using calcined activated 'Hwangto'(Metakaolin). Because Hwangto includes the SiO2 of 50%, "Pozzolan reaction" occurs in the activated Hwangto mixed with Ca(OH)₂. 2SiO₂ + 3Ca(OH)₂→ 3CaO·2SiO₂·3H₂O. Therefore, the result of the mixing reaction of activated Hwangto mixed with lime and cement was that the fluidity and compressive strength increased and drying shrinkage decreased significantly. High-reactive metakaolin has shown the productive possibility of expanding the applications of high performance plastering materials.

보육시설 교사를 대상으로 하는 환경교육 프로그램의 개발

안지연,윤재웅,안옥희 영남대학교 지역발전연구소 1999 새마을지역개발연구 Vol.25 No.-

It is very important for preschool child to environment education in child care and education institution. However only few studies concerned to concrete education program. Therefore this study was environment education program for teacher in child care and education institution. Environment education program were consist of four steps; general idea of environment education, component abstract of environment education program for child, give motivation with development to environment education program, application of environment education program.